Many people have tried to say that the proof that reptiles evolved
into birds is to be found in a fossil bird called Archaeopteryx, which
shows claws on its fossilized feathered wings. But all the living birds with
claws on their wings are obviously birds! Archaeopteryx and the living
‘clawed’ birds tell us only that some kinds of birds have wing claws
and some don’t. Such claws are not something new in birds, and they certainly
don’t show that birds with them are any more reptile-like than birds without
such claws.